202 EPILOBIACEAE. 



— S. Eiver valley near Safe Harbor. — Schists. — Sum. — Swamp-loosesteife. 

 Water- AviLLow. 



3. LYTHE.UM L. Herbs or shrubs. Leaf -blades entire. Flowers axil- 

 lary or in terminal spikes or racemes. Sepals 4-6, alternating with spreading 

 teeth. Petals 4-6, nearly equal. Stamens adnate to the lower part of the 

 hypanthium. Embryo with aurieled cotyledons. 



1. L. Salicaria L. Plant perennial, 1 m. tall or less, with finely pubescent 

 branches: leaf -blades lanceolate to linear-lanceolate, 3-11 cm. long, acute or 

 acuminate at the apex, cordate and clasping at the base: panicle many- 

 flowered, showy: hypanthium 5-6 mm. long, ribbed: sepals deltoid, A-i as 

 long as the slender, subulate appendages: petals magenta, oblong or nearly so, 

 8-10 mm. long: capsule oblong, shorter than the hypanthium. — W. Swamps, 

 near Columbia. Nat. of Eu. — Sum. — Loosestrife. 



4. PABSONSIA P. Br. Herbs or woody plants, mostly clammy-pubescent. 

 Leaf -blades entire. Flowers axillary, or in terminal spikes or racemes. Sepals 

 6, alternating with small teeth. Petals 6, unequal. Stamens adnate to near 

 the top of the hypanthium. Embryo with orbicular cotyledons. 



1. P. petiolata (L.) Eusby. Plants annual, 1-7 dm. tall: leaf -blades lanceo- 

 late to ovate-lanceolate, 1-1.5 cm. long: petals purple, mostly ovate, the upper 

 ones 4.5-5.5 mm. long: capsules 6-8 mm. long. — Common, in fields and woods, 

 and on roadsides. — Sum. — Clammy-weed. 



Family 3. EPILOBIACEAE. Evening-primrose Family. 



Herbs or rarely shrubs. Leaves alternate or opposite : blades simple. 

 Flowers typically perfect. Hypanthium often elongate. Calyx of 2-6, 

 usually 4, sepals. Corolla of 2-9, usually 4, petals, or rarely wanting. 

 Androecium of as many stamens as the sepals, or twice as many. Gynoe- 

 cium of several, usually 4, united carpels. Ovary 1-6-celled, usually 4- 

 celled, inferior. Styles united. Fruit capsular or nut-like. 



Floral whorls of 4 parts or more. 



Fruit a many-seeds capsule, opening by valves or by a pore, or by the breaking 

 down of the walls. 

 Hypanthium not prolonged beyond the ovary. 

 Seed naked, i. e., without a tuft or hairs. 



Leaves opposite : stems prostrate, creeping or floating : flowers sessile 



or nearly so : corolla wanting or very small. 1. Isnaedia. 



Leaves alternate : stems erect : flowers peduncled : 



corolla showy. 2. Ludwigia. 



Seeds furnished with a tuft of silky hairs. 3. Chamaenerion. 



Hypanthium prolonged beyond the ovary. 



Seeds with a tuft of silky hairs. 4. Epilobium. 



Seeds naked or merely tuberculate. 



Flowers with all the stamens equal in length. 5. Oenotheea. 



Flowers with the alternate stamens longer. 0. Kneiffia. 



Fruit indehiscent, nut-like. 7. Gaura. 



Floral whorls of 2 parts. 8. Circaea. 



1. ISNABDIA L. Perennial succulent herbs. Leaf -blades relatively wide. 

 Flowers axillary. Sepals 4, broad. Petals minute, reddish to greenish, or 

 wanting. Filaments very short. Ovary short. Style wanting or nearly so. 

 Capsule obovoid or turbinate. 



1. I. palustris L. Stem diffusely branched: leaf-blades spatulate to oval or 

 ovate, 1.5-2.5 cm. long: hypanthium glabrous: sepals triangular: petals want- 

 ing or minute and reddish : capsules 3-4 mm. long. — Common, in swamps. — 

 Sum. — Marsh-purslane. Water-purslane. 



